Baffle type muffler with plural expansion chambers



ep 1951 P. A. LIEVENSE ETAL 2,567,568

BAFFLE TYPE MUFFLER WITH PLURAL EXPANSIQN CHAMBERS Filed Aug. 25. 1949 .ITNVENTOR. Pezer 4 L1 lag/7J6 7l//l dw ATTOK MEX Patented Sept. 11, 1951 OFFICE BAFFLE TYPE MUFFLER WITH PLURAL EXPANSION CHAIVIBERS Peter A. Lievense and Harry T. Phillips, Jackson, Mich.

Application August 25, 1949, Serial No. 112,323

This invention relates to improvements in baflle type muffler with plural. expansion chambers.

The principal objects of this invention are:

First, to provide a mufller forsilencing the exhaust of internal combustion engines which mufiler is extremely efiective and inexpensive to construct.

Second, to provide a mufiler of small diameter so as to require a. minimum of vertical space beneath a vehicle.

Third, to provide a mufiier which requires no outer body or casing.

Fourth, to provide a mufiier which eliminates back pressure on the internal combustion engme.

Fifth, to providea muffler which isentirely self sustaining and requires support only at its ends where it is connected to the exhaust pipe of an engine and the tail pipe of an automobile.

Other objects and advantages relativeto" details of our invention will be apparent from a consideration of the following description: and claims.

The: drawings, of which there-is one sheet, illustrate a preferred form of our mufiler.

Fig. l is a fragmentary elevational view of the muffler partially broken away in longitudinal cross section.

Fig. 2 is a transverse cross sectional view through one section of the mufiler taken along the plane of line 22 of Fig. 1..

Our mufiler consists of a series of similar. body elements joined together to form an elongated mufiler structure. It should. be understood that as many of the body elements are used as are required to adapt the mufller to the type of engine. We have. found that. for the. average automobile. engine of. eight cylinders,.between six and eight of the body elements connected in series provide satisfactory znnffling action,

Each body element. consistsof a straight-cylindrical portion2 joined with and merging into an expanding forwardly tapering conical portion 3. The end of. the. cylindricalportion is closed by a wall 4 which is securedby welding as at;5. The wall of the cylindrical portion is provided with a plurality of uniformly positioned apertures 6. The sum of the areas of the apertures 5 is at least equal to the cross sectional area of the cylindrical portion 2.

The cylindrical portion 2A of the first body element I is arranged to receive the end of. the exhaust pipe I of an internal combustion engine. The mufller isconveniently supported-at its 9 Claims. (Cl. 18157) forward end by attachment to the exhaust pipe which is in turn supported inany suitable fashion. The cylindrical portion of the next succeedin body element is disposed through the rear wall 8 of the preceding element and concentrically supported within the conical portion 3' of the preceding body element, the joints being made gas-tight by welding as' at 9-. It will be noted that the inner end of the cylindrical. portion 2 is thus located in spaced relationship with the inside of the conical portion 3 midway of the length of the latter, thus forming. an annular space It), the cross sectional area of which is considerably smaller than the cross sectional area of the cylindrical portion 2.

Each of the several body elements lare joined successively to the preceding body element as just described until the final body element, which is connected to the tailpipe II. Preferably the tail pipe is provided with a cylindrical portion i2 nesting within the final body element in the same manner as the cylindrical portion of the body element and is' sealed to the conical end of the final body element by the annular wall i3.

The foregoing construction provides a series of cylindrical chambers of approximately the same cross sectional area as the area of the exhaust pipe. Each cylindrical chamber opens to an expanding conical chamber with an annular constricted passage at its end opening to the wall of the next succeeding cylindrical chamber. Thus the exhaust gases are caused to pass repeatedly through a passage which may be referred to as normal size, being equal to the size of the exhaust pipe, and then expand slightly into the conical passage; after which. they are constricted before re-expanding intoa successive passage of normal size. This action of the gases has been found to effectively m'ufile the noises of the exhaust without creating back pressure on the internal combustion engine;

A11 joints in the mufiler areeasily made by external welding operations as the end plugs 4 are installed prior to assembly of the body elements. The muffler isof small: cross section so that it does not project very far below an automobile body and is thus not liable to be torn off byobstruc tions in the road. No external housing orjacket is required for the muffler; thus further'reducing the cost of manufacture.

' Having thus described ourinvention, what-we claim as new and desire to" secure by Letters Patent is:

l. A mufiler for internal combustion engines comprising aseries of body elements; each'oi said elements having a cylindrical leading portion merging into an outwardly diverging conical portion, the cylindrical portion of each succeeding body element being centrally disposed within the conical portion of the preceding body element with its inner nd spaced from the wall of the conical portion to form therewith an annular passage of smaller cross sectional area than the area of said cylindrical portion, the sides of each succeeding cylindrical portion forming openings of cross sectional area at least equal to the cross sectional area of the cylindrical portion, a wall closing the inner end of each succeeding cylindrical portion, and annular walls joining the divergent ends of each conical portion to the outsides oi the cylindrical portions of each succeeding body element, said body elements being joined in mutually self supporting fashion and having the exterior of their conical portions exposed to the atmosphere.

2. A mufller for internal combustion engines comprising a series of body elements, each of said elements having a cylindrical leading portion merging into an outwardly divering conical portion, the cylindrical portion of each succeeding body element being disposed within the conical portion of the preceding body element with its inner end spaced from the wall of the conical port on to form therewith an annular passage of smaller cross sectional area than the area of said cylindrical portion, the sides of each succeeding cylindrical portion forming openings, a wall closing the inner end of each succeeding cylindrical portion, and annular walls joining the divergent ends of each conical portion to the outsides of the cylindrical portions of each succeeding body element.

3. A muffier for internal combustion engines comprising a series of body elements, each of said elements having a cylindrical leading portion merging into an outwardly diverging conical portion, the cylindrical portion-of each succeeding body element being disposed within the conical portion of the preceding body element with its inner end spaced from the wall of the conical portion to form therewith an annular passage, the sides of each succeeding cylindrical portion forming openings, a wall closing the inner end of each succeeding cylindrical portion, and annular walls joining the divergent ends of each conical portion to the outsides of the succeeding body element.

4. A muffler for internal combustion engines comprising a series of body elements, each of said elements having a tubular gas entrance portion merging into an outwardly diverging portion, the tubular portion of each succeeding body element being disposed within the diverging portion of the preceding body element with its inner end spaced from the wall of the diverging portion to form an annular passage of smaller cross sectional area than the area of said tubular portion, the sides of each succeeding tubular portion forming openings of cross sectional area at least equal to the cross sectional area of the tubular portion,

a wall closing the inner end of each succeeding tubular portion, and annular walls joining the divergent ends of each diverging portion to the outsides of the tubular portion of each succeeding body element.

5. A muffler for internal combustion engines comprising a series of body elements, each of said elements having a tubular gas entrance portion merging into an outwardly diverging portion, the tubular portion of eachsucceeding body element being disposed centrally within the diverging portion of the preceding body element with its inner end spaced from the wall of the diverging portion to form an annular passage, the sides of each succeeding tubular portion forming openings, a wall closing the inner end of each succeeding tubular portion, and annular walls joining the divergent ends of each diverging portion to the outsides of the succeeding body element.

6. A muffler for internal combustion engines comprising an aligned series of body elements, each element comprising a cylindrical front portion merging into an outwardly diverging conical rear portion of substanaially greater diameter at its rear end than the cylindrical portion, the-cylindrical portion being closed at its front end and having a plurality of openings in its side wall, and end walls for the rear end of said elements, the cylindrical portions of one element being disposed through the rear wall 01' the preceding element concentrically of the conical portion of the preceding element and with its side wall openings opening into the preceding element, the relative diameters of the cylindrical portions and the conical portions being such that there is an annular space around each cylindrical portion, the elements being connected and supported by said rear walls in a unitary assembly.

'7.'A muiller for internal combustion engines comprising an aligned series of body elements,

each having a cylindrical front portion and an outwardly diverging conical rear portion merging into the front portion and of substantially greater diameter at its rear end than the cylindrical portion, and end walls for the rear ends of the elements, the cylindrical portion of one element being arranged through and supported concentrically within the conical portion of the preceding element, the cylindrical portion being closed at its forward end and having openings in its side wall opening to the annular space surrounding the cylindrical portions, which space is open to the preceding element, the elements coacting to provide a series of connected expan sion chambers.

'8. A muilier for internal combustion engines comprising a series of body elements having connected tubular inlet portions and outwardly tapering expansion chamber portions, succeeding elements of the series being arranged with their inlet portions concentrically within the large ends of the expansion chamber portions of preceding elements, each preceding element having an end wall across the large end of its expansion chamber portion through which the inlet portion of the next succeeding element is disposed and secured, there being an annular space between the inlet portions and the surrounding expansion chamber portions, the forward end of each succeeding inlet portion being closed, the side walls of said inlet portions being provided with a plurality of inlet openings, said end walls constituting the only supporting connection between the elements, the interiors of the elements being unobstructed except as obstructed by said inlet portions.

9. A muffler for internal combustion engines: comprising a series of body elements having connected tubular inlet portions and outwardly tapering expansion chamber portions, succeeding elements of the series being arranged with their inlet portions concentrically Within the large ends of the expansion chamber portions of preceding elements, each preceding element having 5 6 an end wall across the large end of its expansion EF NCES CITED chamber portion through which the inlet portion The followin references are of record in the of the next succeeding element is disposed and fil f this patent; secured, there being an annular space between the inlet portions and the surrounding expansion 5 N D ATES PATENTS chamber portions, the forward end of each suc- Number Name Date seeding inlet portion being closed, the side walls 779,024 Buchner Jan. 3, 1905 of said inlet portions being provided with a plu- 1,024,638 Lewis 30 1912 W of inlet openings- 1,162,064 Hutton Nov. 30, 1915 PETER LIEVENSE- 10 1,611,475 Maxim Dec. 21, 1926 HARRY T. PHILLIPS. 

